Telescopic valve apparatus



M. B. CONRAD TELESCOPIC VALVE APPARATUS June 18, 1963 2 Sheets-Sheet 1Original Filed April 21, 1958 Morfm B Con rad,

INVENTOR United States Patent 3,094,308 TELESCOPIC VALVE APPARATUSMartin B. Conrad, Downey, Califl, assignor to Baker Oil gools, Inc., LosAngeles, Calif., a corporation of Caliorma Original application Apr. 21,1958, Ser. No. 729,972, now Patent No. 2,984,451, dated May 16, 1961.Divided and this application Mar. 28, 1960, Ser. No. 17,899

4 Claims. (Cl. 251297) The present invention relates to valve apparatus,and more particularly to valve apparatus adapted to be used in :a wellbore in conjunction with a tubular string disposed therein.

The present application is l3. division of my application forSubsurfiace Valve Apparatus, Serial No. 729,972, filed April 21, 1958,now Patent No. 2,984,451, granted May 16, 1961.

An object of the invention is to provide an improved valve apparatusembodying members that telescope with respect to one another in placingthe valve apparatus selectively in open or closed condition, in whichthe valve apparatus is rele asably retained in the open condition, inthe closed condition, or in both conditions, and in which substantiallongitudinal force is required to release the valve apparatus from aparticular condition, thereby preventing inadvertent telescoping betweenthe valve members.

This invention possesses many other advantages, and has other objectswhich may be made more clearly ap parent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevation of an apparatus embodying the invention;

FIG. 2 is a longitudinal section through the apparatus, the valve beingshown in closed position;

FIG. 3 is a view similar to FIG. 2 illustrating the valve in openposition;

FIG. 4 is a cross-section taken along the line 44 on FIG. 1;

FIG. 5 is a cross-section taken along the line 55 on FIG. 1;

FIG. 6 is an enlarged fragmentary longitudinal section through the headand valve seat portion of the apparatus;

FIG. 7 is a view similar to FIG. 6, the valve being fully closed.

The valve apparatus A shown in the drawings is specifically designed foruse in a well bore to control flow of fluid between the interior and theexterior of a tubular string B, such as drill pipe or tubing, extendingto the top of the hole. The valve apparatus may be used in conjunctionwith a lower well tool C, of which only the body or mandrel portion isdisclosed, this lower well tool being of the type that can be anchoredto a well casing against longitudinal movement therein, the casing beingdisposed in the well bore.

The valve apparatus A includes an outer housing or outer-tubular member10 telescopically arranged with respect to an inner tubular member ormandrel 11. The housing may be secured to the tubular string B and themandrel to the lower well tool C, or the apparatus can be inverted withthe mandrel secured to the tubular string and the housing to the welltool. As shown, the outer tubular member 10 includes an upper housingsection or sub 12 provided with an upper threaded box 13 for threadedattachment to the tubular string B. The inner tubular member 11 may havea threaded pin 14 thereon for threaded attachment to the lower tool bodyor mandrel C. The outer tubular member 10 also includes a lower housingsection which is threadedly secured to the upper housing section 12 andis slidable along the periphery of the inner tubular member or mandrel11. This lower housing section has one or a plurality of side openingsor ports 16 through its wall and below the lower end of the upperhousing section or sub 12, to permit fluid to pass between the interiorand the exterior of the valve apparatus when it is in open condition.These side openings or ports 16 may be made quite large, their largearea allowing relatively unimpeded fluid flow between the interior andexterior of the valve apparatus when in its fully open condition.

The valve apparatus includes a valve seat 17 on the lower end of theupper housing section 12, which is preferably constituted as a separatepart for ease and economy of replacement in the event it becomes worn.This valve seat 17 is clamped against the lower end of the upper housingsection by a shoulder 18 on the lower housing section 15 engaging thelower outer portion of the valve seat. Leakage of fluid between theupper end of the valve seat 117 and the lower end of the sub 12 isprevented by a suitable gasket or seal ring 19, such as a rubber orrubber-like 0 ring, mounted in an annular or end groove 20 in the lowerend of the housing and sealingly engaging the upper end of the valveseat.

Mounted on the upper end of the inner tubular member 11, and preferablymade separate therefrom, is a metallic valve head 21, the lower end ofwhich is clamped against the upper end of the inner tubular member 11 bya nut 22 threaded on the mandrel 11 and having an upper inwardlydirected flange 23 engaging an upper outer surface of the metallic valvehead. Leakage of fluid between the lower end of the valve head 21 andthe upper end of the inner tubular member 11 is prevented by a suitableseal ring gasket 24, in the form of a rubber or rubber-like O ring,disposed in an annular end groove 25 in the upper end of the innertubular member 11 and sealingly engaging the lower end of the valvehead.

The valve head 21 has an upwardly extending annular projection 26integral therewith adapted to closely fit within an opposed downwardlyopening annular end groove 27 in the valve seat 17, with the upper end28 of the projection engaging the base 29 of the groove When the valveis in closed position. The inner surface 30 of the projection 26 and itsouter surface 31 preferably make a fairly close sliding fit with theinner and outer side walls 32, 33 of the groove 27 for a purpose thatwill appear hereinafter.

Mounted on the valve head 21 are inner and outer seal rings 34, 35, theinner seal ring 34 being disposed within the confines of the projection26 and engaging its inner side surface 30, this seal ring having a loweroutwardly directed flange 36 disposed within a companion internal groove37 in the projection. The outer seal ring 35 engages the outer side wallor surface 31 of the projection and has an inwardly directed flange 38received within a companion groove 39 in the projection. Actually, theinner and outer seal rings 34, 35, which may be made of rubber orrubber-like material, are :molded to the valve head 21 and in thegrooves 37, 39, the inside diameter of the inner seal ring 34 beingsubstantially equal to inside diameter of the valve head 21, outer ends40 of both seal rings terminating below and inwardly of the upper orouterend 28 of the projection 26. The parts are so proportioned that theends 40 of the inner and outer seal rings engage the end face 41 of thevalve seat and are compressed to some extent thereagainst before the endPatented June 18, 1963' 28 of the projection 26 engages the base 29 ofthe annular groove in the valve seat 17.

It is to be noted that the inside diameter of the upper sub 12, valveseat 17, valve head 21, inner seal ring 34, and inner tubular member 11are preferably substantially the same, so that there is an unobstructedcontinuous inner wall provided when the valve is in closed position forthe passage of fluid through the valve apparatus. This inside diameteris preferably no less than the inside diameter through the tubing stringB, presenting no restrictions in the valve device to the flow of fluentmaterial therethrough, or to the passage of objects, such as perforatingguns and the like, therethrough, which may be used below the valveapparatus and then withdrawn through it.

The valve is in the closed position when the inner and outer tubularmembers 11, occupy a contracted position relative to one another, withthe inner and outer seal rings 34, 35 engaging the valve seat 17 and thevalve head projection 26 disposed fully within the annular groove 27 andin engagement with the base 29 of the groove. The valve member is placedin an open position upon relative extending of the inner and outertubular members 11, 10 with respect to one another. Thus, the outertubular member 10 is elevated with respect to the inner tubular member11 to remove the valve head 21 and seal rings 34, 35 from the companionvalve seat 17 and to elevate the side openings or ports 16 almostcompletely above the valve head 21 and seal rings 34, 35, there thenbeing large openings 16 through the apparatus permitting flow of fluidbetween the interior and exterior thereof, such as disclosed in FIG. 3.Such open position of the valve is determined by engagement of aninwardly directed stop shoulder 45 on the lower housing section with acompanion stop shoulder 46 thereabove projecting outwardly from theinner tubular member 11.

In the form of the invention disclosed in the drawings, the valveapparatus is preferably releasably retained in the closed position andalso releasably retained in the open position, there being a substantiallongitudinal force required to shift the valve between such positions.The releasable retention is secured in the present instance by means ofa releasable latch device provided between the inner and outer tubularmembers 11, 10. Thus, the outer tubular member, or its lower housingsection 15, has a plurality of depending legs 50 integral therewithbelow the inwardly directed flange 45. These depending legs may beformed by providing circumferentially spaced slots 51 through the lowerhousing section 15 extending from its lower end to the flange 45. Thelegs 50 terminate in inwardly directed foot portions 52 having upper camsurfaces 53 inclined in a downward and inward direction for engagementwith a companion lower calm shoulder or inclined surface 54 on themandrel 11. When so engaged, the valve is releasably retained in theclosed position shown in FIGS. 1 and 2. The foot portions 52 also havelower inclined cam surfaces 55 that taper in an upward and inwarddirection for engagement with a companion tapered cam surface 56 formedon the mandrel 11 as the lower side of a circumferential groove 57 anappropriate distance above the lower cam shoulder or surface 54. Whenthe feet 52 are disposed in such groove 57, the valve is in the openposition, as illustrated in FIG. 3.

Assuming the valve to be in the closed position shown in FIGS. 1 and 2,with the latch feet 52 engaged under the lower cam shoulder 54 on themandrel v11, the valve can only be shifted to an open position byovercoming the inherent spring force of the legs 50; that is, byexpanding the legs outwardly. T he taking of a sufficient upward pull onthe tubular string B and the outer tubular member 10, with the innertubular member 11 held stationary by the anchoring of the lower tool Cto the well casing, will cause the inclined cam surface 54 to expand andcam the foot portions 52 outwardly sufficiently until the foot portionsare no longer disposed under the shoulder 54,

whereupon the foot portions 52 can slide along the periphery of themandrel 11, the outer housing member 10 then moving upwardly relative tothe inner mandrel to elevate the valve seat 17 from the head 21 anddispose the ports 16 almost fully above the valve head 21 and its sealrings 34, 35. This upward position is limited by the coengagement of thestop shoulders 45, 46, at which time the feet 52 will shift inherentlyinto the upper mandrel groove 57, releasably retaining the valve in theopen position.

If it is desired to reclose the valve, then a suflicient downward forceis imposed through the tubular string B on the outer tubular member 10,the inner tubular mem ber 11 being prevented from moving longitudinallyby the anchoring of the lower tool C against the well casing, thecoengaging cam surfaces 55, 56 expanding the feet 52 and legs outwardlyfrom the groove 57, whereupon the legs can slide down along theperipheral surface of the mandrel 11 once again, until the valve seat 17receives the head projection 26 and the inner and outer seal rings 34,35 again are in sealing engagement with the valve seat. At this time,the feet 52 can retract inherently to a position under the lower camsurface or shoulder 54 on the mandrel 11, releasably holding the valvein closed position.

The force required to shift the legs 50 from engagement with the lowerand upper shoulders 54, 56 can be quite substantial. For example, atotal upward pull or downward force of 3000 lbs. might be necessary torelease the legs from the lower shoulder 54 or to release them from theupper cam surface 56, depending upon the open or closed condition of thevalve.

The valve apparatus is capable of withstanding relatively high pressuredifferentials internally of the apparatus and also relatively highpressure differentials externally of the apparatus without the pliant,elastic seal rings 34, 35 being blown out or forced out of theirassembled position on the apparatus when the valve is being moved to anopen condition or to a closed condition. It is to be noted that when thevalve is in the closed condition, the head projection 26 is disposedfully within the groove 27, with its end 28 in contact with the base 29of the valve seat groove. Assuming a pressure differential to be presentinternally of the tubular members 10, 11, such pressure is acting in anoutward direction against the inner seal ring 34, forcing it outwardlyagainst the inner side 30 of the projection 26 and also against thelower face 41 of the valve seat 17. The seal ring 34 cannot be displacedfrom its assembled relation since the clearance space between theprojection 26 and the inner side 32 of the valve seat groove 27 is verysmall; in fact being so small that none of the seal ring material can beforced into such space. A firm elastic seal is thus provided between thevalve head 21 and the valve seat 17, preventing leakage. This seal issupplemented by the metal-to-metal contact between the end 28 of theprojection and the base 29 of the groove 27, that forms another valveseating surface. Thus, there are two main sealing regions pre ventingleakage of fluid from the interior of the apparatus to the exterior, oneof which is provided by the sealing engagement of the inner seal ring 34with the face 41 of the valve seat 17, and the other provided by themetallic sealing engagement of the end 28 of the head projection 26 withthe base 29 of the valve seat groove 27.

There is yet a further metal-to-metal sealing surface provided betweenthe projection 26 and the valve seat 17. In the event of comparativelyhigh pressure differentials internally of the apparatus, such pressuresare acting outwardly on the inner seal ring 34 and are exerted throughsuch inner seal ring in an outward direction upon the projection 26,deforming such projection to a slight extent, which is suflicient toengage the outer side 31 of the projection with the outer side wall 33of the valve seat groove 27, holding them in firm sealing contact withone another, and thus providing a metal-tmmetal side seal between thehead projection and the valve seat.

With a pressure differential internally of the apparatus, if the valveis to be opened, such opening will occur without blowing or forcing theinner seal ring 34 out of its assembled relation on the valve head. Asthe outer tubular member is moved upwardly relative tothe inner tubularmember .11, the inner seal ring 3-4 will disengage from the end face 41of the valve seat 17 before the projection 26 is removed from the andgroove 27 of the valve seat (FIG. 6). Thus, during the time that theinner seal ring 34 is being moved to a disengaged position from the endface 41 of the valve seat, it is being backed up by the projection 26,which is still making a close fit with the inner side 32 of the valveseat groove 27. After the inner seal ring 34 disengages from the valveseat 17, but before the projection 26 moves out of the groove 27, theinternal pressure is being applied to the seal ring 34 on both its innerand outer sides, the inner seal ring then having no pressuredifferential applied to it. Thereafter, the projection 26 will move outof the seat groove 27 and allow fluid to flow therearound. At this time,the inner and outer seal rings 34, 35 have been substantially removedfrom the face 41 of the valve seat 17 and are subjected to substantiallyno pressure differentials. The valve can then be shifted completely toits fully open position.

Assuming the valve to be in the closed position shown in FIG. 2, and acomparatively high pressure differential present externally of thedevice, the valve is held in the closed position without fear that theouter seal ring 35 will be removed from its appropriate position on thevalve head 21 and in sealing engagement with the end face 41 of thevalve seat 17. The pressure is exerted inwardly on the outer seal ring35. Such pressure cannot force the ring 35 into the small clearancespace existing between the outer surface 31 of the projection and theouter side wall 33 of the valve seat groove 27, 'as was true of theinner seal ring. The sealing action of the outer seal ring 35 againstthe end face 41 of the valve seat is supplemented by a metal-tometa lend seal provided between the end face 28 of the projection and the base29 of the valve seat groove. Under rather high pressure differentialconditions, the inward force exerted on the outer seal ring 35 istransferred therethrough to the projection 26, deforming or urging itinwardly so that its inner side surface 30 engages the inner side wall32 of the groove 27, thereby providing an additional side metal-to-metalseal, or a total of three seals precluding leakage of fluid through theclosed and engaged valve elements.

In the event the valve is to be shifted to open position with arelatively high pressure differential externally of the apparatus, theelevation of the outer tubular member 10 relative to the inner tubularmember 11 will first move the valve seat 17 upwardly to disenage its endface 41 from the end'of the outer seal ring 35, at which time theprojection 26 is still disposed within the valve seat groove 27 (FIG.6). The external pressure will become equalized around the outer sealring 35 before the backing afforded by the projection 26 within thevalve seat groove 27 becomes non-existent. Thereafter, the elevation ofthe valve seat 17 completely from the projection 26 can occur withoutany of the pliant, elastic sealing elements being subject to highpressure differentials tending to blow or force them out of theirassembled position on the valve head, the valve being shifted to itsfully open position, shown in FIG. 3.

With the valve in the open condition, it can be shifted to the closedposition once again without fear of forcing or extruding the inner andouter seal rings 34, 35 from their assembled position. Each seal ringwill have no pressure differential imposed upon it until after theprojection 26 enters the annular end groove 27 in the valve seat 17;whereupon any pressure differential imposed on the inner ring 34, in theevent the internal pressure predominates, will force the inner ringoutwardly against the projection 26, which is making a close sliding fitwith the inner side wall 32 of the groove, allowing no space throughwhich the packing material can be extruded. A complete closing of thevalve will then shift the inner and outer seal rings 34, 35 into sealingengagement with the end face 41 of the valve seat to the extent limitedby engagement of the end 28 of the projection with the base 29 of thevalve seat groove.

Similarly, if the valve is shifted to a closed position with thepressure dilferential predominating externally of the apparatus, theprojection 26 will move into the groove 27 before the outer seal ring 35engages the valve seat 17 and has a pressure differential imposedthereon. At this time, the pressure is urging the outer seal ring 35inwardly, but it is fully backed up by the projection 26 disposed withinthe groove 27, the valve being moved to the fully closed positionreferred to above.

The valve arrangement illustrated has yet a further advantage. With thevalve in the closed position and a pressure differential internally ofthe apparatus, only a small end area is available tending to shift thevalve to an open position. Such end area at most will be the annulararea R of the end face 41 of the valve seat 17 between the inner wall 60of the valve seat and the inner side 32 of the valve seat groove 27. Itis evident that the pressure acting over this relatively small annulararea R will not exert a very great force tending to shift the valve toan open position. In fact, the force, even under high pressureconditions, could very well be less than the holding force of the latchlegs 50 under the lower cam or holding surface 54 on the inner mandrel11.

Similarly, any pressure differentials externally of the apparatustending to shift the outer tubular member upwardly from its closedposition can act only over a relatively small difierential area becauseof the relative arrangement of the parts.

Assuming that the inner tubular member 11 is not held from longitudinalmovement by the lower tool C, any internal pressure would still fail toshift the valve inadvertently from a closed to an open condition, sincethe internal pressure is acting over the end area R referred to abovebetween the inner surface 61 of the seal ring 34 and the inner surface30 of the projection 26, which is substan tially the same as the endarea of the mandrel 11 subject to fluid or of the lower tool -C attachedthereto over which the fluid pressure is acting in an upward direction.The two areas practically counterbalance one another. In the event thepressure differential exists externally of the apparatus and the lowertool C is not anchoring the mandrel 11 to the well casing, then theupwardly facing and the downwardly facing end areas of the mandrel 11over which the external pressure is acting substantially counterbalanceone another, there being substantially no pressure force tending toshift the mandrel in either an upward or a downward direction.

It is preferred to transmit turning effort or torque between the innerand outer tubular members 11, 10 for all relative telescopic positionstherebetween. To accomplish this purpose, a longitudinally extending keymay be suitably secured, as by use of welding material 71, to the innertubular member 11, this key having an extended length and being slidablyreceived within a longitudinal groove 72 in the flange 45 of the outertubular member 10. Thus, for all telescopic positions of the inner andouter tubular members 11, 10, turning effort can be transmitted from theouter tubular member 10, through its flange 45 and the longitudinallyextending key 70 to the inner tubular member 11, this turning effortthen being transferred to the lower tool C for suitable actuationthereof.

The valve apparatus disclosed is capable of withstanding very highpressure differentials without failure of its parts, despite repeatedopening and closing of the apparatus under such high pressuredifferential conditions. The apparatus is short and compact, iscomparatively economical to manufacture, and easy to maintain. Thesealing elements 34, 35 have a long life, which is also true of theother parts, the replacement rate of parts being relatively low. Thefact that the side openings 16 in the valve have a large area andcommunicate directly with the interior of the valve apparatus, as wellas with the exterior thereof, minimizes fluid erosion on the parts whenthe valve is in open position. When it is in closed position, there is aminimum of fluid erosion on the parts, inasmuch as there is astraight-through passage through the valve apparatus, as is evident fromFIG. 2. The arrangement of the coengageable sealing portions of theapparatus are such that the rubber or rubber-like seal elements 34, 35cannot be blown or otherwise removed from the valve apparatus under highpressure differential conditions and during opening and closing of thevalve apparatus, regardless of the existence of the pressuredifferential internally of the apparatus or externally thereof. In fact,a plurality of seals are provided; pliant, elastic seals as well asmetal-to-metal seals that supplement one another and assure againstleakage of fluid through the apparatus. The arrangement is such thatthere is only a relatively small resultant or differential area in thevalve apparatus subject to pressure differentials and tending to shiftthe apparatus from its closed to its open condition. Whatever resultanthydraulic forces are present tending to shift the valve from the closedcondition are easily overcome by the releasable latch device, which canbe devised to withstand substantial longitudinal forces prior torelease. The force required depends upon the thickness, material, andnumber of the legs 50 and their foot portions 52, and the degree ofinclination of the coengageable cam surfaces 53, 54.

I claim:

1. In valve apparatus to be disposed in a tubular string located in awell bore: an outer member; an inner member telescoped within said outermember; means on the end portions of each of said members for connectingsaid members to adjacent tubular sections of the tubular string;coengageable means on said members to close the valve apparatus whensaid members are in one telescoped position with respect to each other,said means being disengaged to open the valve apparatus when saidmembers are in another telescoped position with respect to each other;releasable latch means for selectively securing said members in saidpositions, including longitudinally spaced circumferentially continuouscam surfaces on said inner member, said outer member having acircumferentially continuous portion and a plurality ofcircumferentially spaced laterally expandible and contractible legssecured to said cylindrical portion, said legs having inwardly extendingportions adapted to selectively engage said cam surfaces, the exteriorsof said continuous portion and legs lying in a cylindrical outer surfaceof said outer member, said inwardly extending portions also beingengageable with the exterior of said inner member between said camsurfaces during shifting of said members between valve opening and valveclosing positions, said portions being shiftable laterally outwardlyfrom engagement with said cam surfaces in response to a predeterminedlongitudinal force imposed by the tubular string upon said members whilethe apparatus is in the well bore; coengageable stop means on saidmembers for limiting the extent of relative telescoping movement betweensaid members to locate said members in said another telescoped positionwith the valve apparatus in open condition; and coengageable stop meanson said members for limiting the extent of relative telescoping movementbetween said members to locate said members in said one telescopedposition with the valve apparatus closed.

2. In valve apparatus to be disposed in a tubular string located in awell bore: an outer member; an inner member telescoped within said outermember; means on the end portions of each of said members for connectingsaid members to adjacent tubular sections of the tubular string;

coengageable means on said members to close the valve apparatus whensaid members are in one telescoped position with respect to each other,said means being disengaged to open the valve apparatus when saidmembers are in another telescoped position with respect to each other;releasable latch means for selectively securing said member-s in saidpositions, including longitudinally spaced circumferentially continuouscam surfaces on said inner member, said outer member having acircumferentially continuous portion and a plurality ofcircumferentially spaced laterally expandible and contractible legsintegral with said cylindrical portion and having inwardly extendingportions integral with said legs and adapted to selectively engage saidcam surfaces, the exteriors of said continuous portion and legs lying ina cylindrical outer surface of said outer member, said inwardlyextending portions also being engageable with the exterior of said innermember between said cam surfaces during shifting of said members betweenvalve opening and valve closing positions, said portions being shiftablelaterally outwardly from engagement with said cam surfaces in responseto a predetermined longitudinal force imposed by the tubular string uponsaid members while the apparatus is in the well bore; coengageable stopmeans on said members for limiting the extent of relative telescopingmovement be tween said members to locate said members in said anothertelescoped position with the valve apparatus in open condition; andcoengageable stop means on said members for limiting the extent ofrelative telescoping movement between said members to locate saidmembers in said one telescoped position with the valve apparatus closed.

3. In valve apparatus to be disposed in a tubular string located in awell bore: an outer member; an inner member telescoped within said outermember; means on the end portions of each of said members for connectingsaid members to adjacent tubular sections of the tubular string; saidouter member having a side port; coengageable means on said members toclose said port when said members are in one telescoped position withrespect to each other, said means being disengaged to open said portwhen said members are in another telescoped position with respect toeach other; releasable latch means for selectively securing said membersin said positions, including longitudinally spaced circumferentiallycontinuous cam surfaces on said inner member, said outer member having acircumferentially continuous portion and a plurality ofcircumferentially spaced laterally expandible and contractible legsintegral with said cylindrical portion and having inwardly extendingportions integral with said legs and adapted to selectively engage saidcam surfaces, the exteriors of said continuous portion and legs lying ina cylindrical outer surface of said outer member, said inwardlyextending portions also being engageable with the exterior of said innermember between said cam surfaces during shifting of said members betweenport opening and port closing positions, said portions being shiftablelaterally outwardly from engagement with said cam surfaces in responseto a predetermined longitudinal force imposed by the tubular string uponsaid members while the apparatus is in the well bore; coengageable stopmeans on said members for limiting the extent of relative telescopingmovement between said members to locate said members in said anothertelescoped position with the valve apparatus in open condition; andcoengageable stop means on said members for limiting the extent ofrelative telescoping movement between said members to locate saidmembers in said one telescoped position with the valve apparatus closed.

4 In valve apparatus to be disposed in a tubular string located in awell bore: an outer member; an inner member telescoped within said outermember; means on the end portions of each of said members for connectingsaid members to adjacent tubular sections of the tubular string; saidouter member having a side port; coengageable means on said members toclose said port when said members are in telescoped, contracted positionwith respect to each other, said means being disengaged to open saidport when said members are in telescoped, extended position with respectto each other; releasable latch means for selectively securing saidmembers in said positions, including longitudinally spacedcircumferentially continuous cam surfaces on said inner member, saidouter member having a circumferentially continuous portion and aplurality of circumferentially spaced laterally expandible andcontractible legs integral with said cylindrical portion and havinginwardly extending portions integral with said legs and adapted toselectively engage said cam surfaces, the exteriors of said continuousportion and legs lying in a cylindrical outer surface of said outermember, said inwardly extending portions also being engageable with theexterior of said inner member between said cam surfaces during shiftingof said members between port opening and port closing positions, saidportions being shiftable laterally outwardly from engagement with saidcam surfaces in response to a predetermined longitudinal force imposedby the tubular string upon said members while the apparatus is in thewell bore; coengageable stop means on said members for limiting theextent of relative telescoping movement between said members to locatesaid members in said telescoped, extended position with the port open;and coengageable stop means on said members for limiting the extent ofrelative telescopic movement between said members to locate said membersin said telescoped, contracted position with the port closed.

References Cited in the file of this patent UNITED STATES PATENTS1,906,891 White May 2, 1933 2,083,714 Keeler June 15, 1937 2,098,520Santiago Nov. 9, 1937 2,690,895 Barcus Oct. 5, 1954 2,727,759 ElliottDec. 20, 1955 2,799,350 Conrad July 16, 1957

1. IN VALVE APPARATUS TO BE DISPOSED IN A TUBULAR STRING LOCATED IN AWELL BORE: AN OUTER MEMBER; AN INNER MEMBER TELESCOPED WITHIN SAID OUTERMEMBER; MEANS ON THE END PORTIONS OF EACH OF SAID MEMBERS FOR CONNECTINGSAID MEMBERS TO ADJACENT TUBULAR SECTIONS OF THE TUBULAR STRING;COENGAGEABLE MEANS ON SAID MEMBERS TO CLOSE THE VALVE APPARATUS WHENSAID MEMBERS ARE IN ONE TELESCOPED POSITION WITH RESPECT TO EACH OTHER,SAID MEANS BEING DISENGAGED TO OPEN THE VALVE APPARATUS WHEN SAIDMEMBERS ARE IN ANOTHER TELESCOPED POSITION WITH RESPECT TO EACH OTHER;RELEASABLE LATCH MEANS FOR SELECTIVELY SECURING SAID MEMBERS IN SAIDPOSITIONS, INCLUDING LONGITUDINALLY SPACED CIRCUMFERENTIALLY CONTINUOUSCAM SURFACES ON SAID INNER MEMBER, SAID OUTER MEMBER HAVING ACIRCUMFERENTIALLY CONTINUOUS PORTION AND A PLURALITY OFCIRCUMFERENTIALLY SPACED LATERALLY EXPANDIBLE AND CONTRACTIBLE LEGSSECURED TO SAID CYLINDRICAL PORTION, SAID LEGS HAVING INWARDLY EXTENDINGPORTIONS ADAPTED TO SELECTIVELY ENGAGE SAID CAM SURFACES, THE EXTERIORSOF SAID CONTINUOUS PORTION AND LEGS LYING IN A CYLINDRICAL OUTER SURFACEOF SAID OUTER MEMBER, SAID INWARDLY EXTENDING PORTIONS ALSO BEINGENGAGEABLE WITH THE EXTERIOR OF SAID INNER MEMBER BETWEEN SAID CAMSURFACES DURING SHIFTING OF SAID MEMBERS BETWEEN VALVE OPENING AND VALVECLOSING POSITIONS, SAID PORTIONS BEING SHIFTABLE LATERALLY OUTWARDLYFROM ENGAGEMENT WITH SAID CAM SURFACES IN RESPONSE TO A PREDETERMINEDLONGITUDINAL FORCE IMPOSED BY THE TUBULAR STRING UPON SAID MEMBERS WHILETHE APPARATUS IS IN THE WELL BORE; COENGAGEABLE STOP MEANS ON SAIDMEMBERS FOR LIMITING THE EXTENT OF RELATIVE TELESCOPING MOVEMENT BETWEENSAID MEMBERS TO LOCATE SAID MEMBERS IN SAID ANOTHER TELESCOPED POSITIONWITH THE VALVE APPARATUS IN OPEN CONDITION; AND COENGAGEABLE STOP MEANSON SAID MEMBERS FOR LIMITING THE EXTENT OF RELATIVE TELESCOPING MOVEMENTBETWEEN SAID MEMBERS TO LOCATE SAID MEMBERS IN SAID ONE TELESCOPEDPOSITION WITH THE VALVE APPARATUS CLOSED.